scholarly journals Bezafibrate Improves Mitochondrial Fission and Function in DNM1L-Deficient Patient Cells

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 301 ◽  
Author(s):  
Liza Douiev ◽  
Ruth Sheffer ◽  
Gabriella Horvath ◽  
Ann Saada
Keyword(s):  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Mitochondrial Fission ◽  
Fibroblast Cell ◽  
Multiple Organ ◽  
Mitochondrial Morphology ◽  
Main Role ◽  
Atp Production ◽  
Organ Systems ◽  
Mitochondrial Functions

Mitochondria are involved in many cellular processes and their main role is cellular energy production. They constantly undergo fission and fusion, and these counteracting processes are under strict balance. The cytosolic dynamin-related protein 1, Drp1, or dynamin-1-like protein (DNM1L) mediates mitochondrial and peroxisomal division. Defects in the DNM1L gene result in a complex neurodevelopmental disorder with heterogeneous symptoms affecting multiple organ systems. Currently there is no curative treatment available for this condition. We have previously described a patient with a de novo heterozygous c.1084G>A (p.G362S) DNM1L mutation and studied the effects of a small molecule, bezafibrate, on mitochondrial functions in this patient’s fibroblasts compared to controls. Bezafibrate normalized growth on glucose-free medium, as well as ATP production and oxygen consumption. It improved mitochondrial morphology in the patient’s fibroblasts, although causing a mild increase in ROS production at the same time. A human foreskin fibroblast cell line overexpressing the p.G362S mutation showed aberrant mitochondrial morphology, which normalized in the presence of bezafibrate. Further studies would be needed to show the consistency of the response to bezafibrate, possibly using fibroblasts from patients with different mutations in DNM1L, and this treatment should be confirmed in clinical trials. However, taking into account the favorable effects in our study, we suggest that bezafibrate could be offered as a treatment option for patients with certain DNM1L mutations.

scholarly journals Bezafibrate Improves Mitochondrial Fission and Function in DNM1L Deficient Patient Cells

2019 ◽  
Author(s):  
Liza Douiev ◽  
Ruth Sheffer ◽  
Gabriella Horvath ◽  
Ann Saada
Keyword(s):  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Mitochondrial Fission ◽  
Multiple Organ ◽  
Mitochondrial Morphology ◽  
Main Role ◽  
Atp Production ◽  
Organ Systems ◽  
Mitochondrial Functions ◽  
And Function

Mitochondria are involved in many cellular processes and their main role is cellular energy production. They constantly undergo fission and fusion, and these counteracting processes are under strict balance. The cytosolic dynamin-related protein 1, Drp1 or dynamin-1-like protein (DNM1L) mediates mitochondrial and peroxisomal division. Defects in the DNM1L gene results in a complex neurodevelopmental disorder with heterogeneous symptoms affecting multiple organ systems. Currently there is no curative treatment available for this condition. We have previously described a patient with a de novo heterozygous c.1084G>A (p.G362S) DNM1L mutation and studied the effects of a small molecule, Bezafibrate, on mitochondrial functions in this patient’s fibroblasts compared to controls. Bezafibrate normalized growth on glucose-free medium, ATP production, oxygen consumption and s improved mitochondrial morphology in patient’s fibroblasts, albeit concomitantly causing a mild increase ROS production. Further studies would be needed to show the consistency of the response to Bezafibrate, possibly using fibroblasts from patients with different mutations in DNM1L, and this treatment should be confirmed in clinical trials. However, taking into account the favorable effects in our study, we suggest that Bezafibrate could be a possible treatment option for patients with certain DNM1L mutations.

Nε-(carboxymethyl) lysine-induced mitochondrial fission and mitophagy cause decreased insulin secretion from β-cells

2015 ◽  
Vol 309 (10) ◽  
pp. E829-E839 ◽  
Author(s):  
Mei-Chen Lo ◽  
Ming-Hong Chen ◽  
Wen-Sen Lee ◽  
Chin-I Lu ◽  
Chuang-Rung Chang ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Fission ◽  
Lipid Peroxide ◽  
Mitochondrial Morphology ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Atp Production ◽  
Mitochondrial Functions ◽  
Carboxymethyl Lysine

Nε-(carboxymethyl) lysine-conjugated bovine serum albumin (CML-BSA) is a major component of advanced glycation end products (AGEs). We hypothesised that AGEs reduce insulin secretion from pancreatic β-cells by damaging mitochondrial functions and inducing mitophagy. Mitochondrial morphology and the occurrence of autophagy were examined in pancreatic islets of diabetic db/db mice and in the cultured CML-BSA-treated insulinoma cell line RIN-m5F. In addition, the effects of α-lipoic acid (ALA) on mitochondria in AGE-damaged tissues were evaluated. The diabetic db/db mouse exhibited an increase in the number of autophagosomes in damaged mitochondria and receptor for AGEs (RAGE). Treatment of db/db mice with ALA for 12 wk increased the number of mitochondria with well-organized cristae and fewer autophagosomes. Treatment of RIN-m5F cells with CML-BSA increased the level of RAGE protein and autophagosome formation, caused mitochondrial dysfunction, and decreased insulin secretion. CML-BSA also reduced mitochondrial membrane potential and ATP production, increased ROS and lipid peroxide production, and caused mitochondrial DNA deletions. Elevated fission protein dynamin-related protein 1 (Drp1) level and mitochondrial fragmentation demonstrated the unbalance of mitochondrial fusion and fission in CML-BSA-treated cells. Additionally, increased levels of Parkin and PTEN-induced putative kinase 1 protein suggest that fragmented mitochondria were associated with increased mitophagic activity, and ALA attenuated the CML-BSA-induced mitophage formation. Our study demonstrated that CML-BSA induced mitochondrial dysfunction and mitophagy in pancreatic β-cells. The findings from this study suggest that increased concentration of AGEs may damage β-cells and reduce insulin secretion.

scholarly journals Porphyromonas gingivalis infection promotes mitochondrial dysfunction through Drp1-dependent mitochondrial fission in endothelial cells

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tong Xu ◽  
Qin Dong ◽  
Yuxiao Luo ◽  
Yanqing Liu ◽  
Liang Gao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Mitochondrial Dysfunction ◽  
Porphyromonas Gingivalis ◽  
Vascular Endothelial Cells ◽  
Mitochondrial Fission ◽  
Mitochondrial Morphology ◽  
Mitochondrial Fragmentation ◽  
Atp Production ◽  
Luminescence Assay ◽  
The Impact

AbstractPorphyromonas gingivalis (P. gingivalis), a key pathogen in periodontitis, has been shown to accelerate the progression of atherosclerosis (AS). However, the definite mechanisms remain elusive. Emerging evidence supports an association between mitochondrial dysfunction and AS. In our study, the impact of P. gingivalis on mitochondrial dysfunction and the potential mechanism were investigated. The mitochondrial morphology of EA.hy926 cells infected with P. gingivalis was assessed by transmission electron microscopy, mitochondrial staining, and quantitative analysis of the mitochondrial network. Fluorescence staining and flow cytometry analysis were performed to determine mitochondrial reactive oxygen species (mtROS) and mitochondrial membrane potential (MMP) levels. Cellular ATP production was examined by a luminescence assay kit. The expression of key fusion and fission proteins was evaluated by western blot and immunofluorescence. Mdivi-1, a specific Drp1 inhibitor, was used to elucidate the role of Drp1 in mitochondrial dysfunction. Our findings showed that P. gingivalis infection induced mitochondrial fragmentation, increased the mtROS levels, and decreased the MMP and ATP concentration in vascular endothelial cells. We observed upregulation of Drp1 (Ser616) phosphorylation and translocation of Drp1 to mitochondria. Mdivi-1 blocked the mitochondrial fragmentation and dysfunction induced by P. gingivalis. Collectively, these results revealed that P. gingivalis infection promoted mitochondrial fragmentation and dysfunction, which was dependent on Drp1. Mitochondrial dysfunction may represent the mechanism by which P. gingivalis exacerbates atherosclerotic lesions.

Effect of MALAT1 in the crosstalk between nucleus and mitochondria on mitochondrial reprogramming in hepatocellular carcinoma cells.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e14711-e14711
Author(s):  
Yijing Zhao ◽  
Jiuwei Cui ◽  
Jifan Hu ◽  
Andrew R Hoffman
Keyword(s):  
Rna Binding ◽  
Transmembrane Protein ◽  
Mitochondrial Morphology ◽  
Mitochondrial Rna ◽  
Mtdna Copy Number ◽  
Mitochondria Dysfunction ◽  
Mt Dna ◽  
Apoptosis Pathway ◽  
Atp Production ◽  
Mitochondrial Functions

e14711 Background: Mitochondria-nuclear crosstalk is a bidirectional pathway of communication between mitochondria and nucleus that influences many cellular and organismal activities. This crosstalk can regulate several oncogenic pathways involved in tumorigenesis. MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), a nucleus-encoded lncRNA, dysregulated in multiple human malignancies is recently found to drive mitochondria dysfunction in Mitochondria-nuclear crosstalk. Methods: RNA sequencing, “RNA reverse transcription-associated trap sequencing” (RAT-seq), RNA immunoprecipitation(RIP), fluorescence in situ hybridization (FISH), were performed to detect the position of the MALAT1, and its interaction protein and DNAs in HepG2 cell line. After silencing MALAT1 by shRNAs, Seahorse, ATP production, lysotracker staining, Western blot, and electronic microscope were used to measure metabolism, ROS amount, mitophagy, apoptosis and mitochondrial morphology of the silencing cell lines. Results: By combining mitochondrial RNA-Seq with FISH, it is surprised to discover that MALAT1 was enriched in the mitochondria of HepG2 cells. Using RAT-seq approach, MALAT1 was found to utilized it 3’-fragment to interact with multiple loci of mitochondrial DNA( D-loop, COX2, ND3, and CYTB ). The RIP and affinity RNA pulldown assays suggested that the RNA-binding protein HuR mediated the transportation of MALAT1 to the mitochondria. Also, mitochondria transmembrane protein mitochondrial carrier 2(MTCH2) is found to interacted MALAT1, suggesting that MALAT1 may through the MTCH2 to get into the inside of the mitochondria. Knockdown of MALAT1 induced multiple abnormalities in mitochondrial functions, including low OXPHOS, low ATP production, reduced mitophagy, declined mtDNA copy number, and activation of the mitochondrial apoptosis pathway. Conclusions: Together, this study greatly expands our knowledge of the nucleus-encoded lncRNA MALAT1 driving the mitochondria dysfunction. Our study establishes MALAT1 as a regulator through interacting with MT-DNA, HuR, MTCH2 protein, revealing a new regulatory mechanism of mitochondria. Many novel nucleus-encoded RNAs existing in mitochondria were identified at the first time, suggesting novel biological functions of lncRNAs, laying the foundation for further clarifying their roles.

MARFAN SYNDROME AND PREGNANCY: CLINICAL IMPLICATIONS AND MANAGEMENT

2010 ◽  
Vol 21 (3) ◽  
pp. 225-241
Author(s):  
ARIADNA C GRIGORIU ◽  
JACK COLMAN ◽  
CANDICE K SILVERSIDES ◽  
RACHEL WALD ◽  
SAMUEL C SIU ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Marfan Syndrome ◽  
Autosomal Dominant ◽  
De Novo ◽  
Connective Tissue Disorder ◽  
Multiple Organ ◽  
Clinical Implications ◽  
Organ Systems

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder that affects multiple organ systems, primarily the cardiovascular, ocular and skeletal. It is the most common inherited condition affecting the heart and the aorta, occurring in 1:5000–1:9800 people. There is no ethnic or gender predisposition; 20 to 35% of cases arise fromde novomutations.

scholarly journals mito-QC illuminates mitophagy and mitochondrial architecture in vivo

2016 ◽  
Vol 214 (3) ◽  
pp. 333-345 ◽  
Author(s):  
Thomas G. McWilliams ◽  
Alan R. Prescott ◽  
George F.G. Allen ◽  
Jevgenia Tamjar ◽  
Michael J. Munson ◽  
...  
Keyword(s):  
Quality Control ◽  
Cell Biology ◽  
Multiple Organ ◽  
Mitochondrial Morphology ◽  
In Vivo Detection ◽  
Developing Heart ◽  
Adult Kidney ◽  
Organ Systems ◽  
Essential Quality

Autophagic turnover of mitochondria, termed mitophagy, is proposed to be an essential quality-control (QC) mechanism of pathophysiological relevance in mammals. However, if and how mitophagy proceeds within specific cellular subtypes in vivo remains unclear, largely because of a lack of tractable tools and models. To address this, we have developed “mito-QC,” a transgenic mouse with a pH-sensitive fluorescent mitochondrial signal. This allows the assessment of mitophagy and mitochondrial architecture in vivo. Using confocal microscopy, we demonstrate that mito-QC is compatible with classical and contemporary techniques in histochemistry and allows unambiguous in vivo detection of mitophagy and mitochondrial morphology at single-cell resolution within multiple organ systems. Strikingly, our model uncovers highly enriched and differential zones of mitophagy in the developing heart and within specific cells of the adult kidney. mito-QC is an experimentally advantageous tool of broad relevance to cell biology researchers within both discovery-based and translational research communities.

scholarly journals Hydrogen Sulfide, an Endogenous Stimulator of Mitochondrial Function in Cancer Cells

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 220
Author(s):  
Csaba Szabo
Keyword(s):  
Dna Repair ◽  
Mitochondrial Dna ◽  
Hydrogen Sulfide ◽  
Cancer Cells ◽  
Mitochondrial Fission ◽  
Cytotoxic Action ◽  
Atp Production ◽  
Mitochondrial Functions ◽  
Mitochondrial Dna Repair ◽  
Stimulation Of

Hydrogen sulfide (H2S) has a long history as toxic gas and environmental hazard; inhibition of cytochrome c oxidase (mitochondrial Complex IV) is viewed as a primary mode of its cytotoxic action. However, studies conducted over the last two decades unveiled multiple biological regulatory roles of H2S as an endogenously produced mammalian gaseous transmitter. Cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST) are currently viewed as the principal mammalian H2S-generating enzymes. In contrast to its inhibitory (toxicological) mitochondrial effects, at lower (physiological) concentrations, H2S serves as a stimulator of electron transport in mammalian mitochondria, by acting as an electron donor—with sulfide:quinone oxidoreductase (SQR) being the immediate electron acceptor. The mitochondrial roles of H2S are significant in various cancer cells, many of which exhibit high expression and partial mitochondrial localization of various H2S producing enzymes. In addition to the stimulation of mitochondrial ATP production, the roles of endogenous H2S in cancer cells include the maintenance of mitochondrial organization (protection against mitochondrial fission) and the maintenance of mitochondrial DNA repair (via the stimulation of the assembly of mitochondrial DNA repair complexes). The current article overviews the state-of-the-art knowledge regarding the mitochondrial functions of endogenously produced H2S in cancer cells.

scholarly journals The pathophysiology of preeclampsia in view of the two-stage model

2012 ◽  
Vol 153 (30) ◽  
pp. 1167-1176 ◽  
Author(s):  
Bálint Alasztics ◽  
Zoltán Kukor ◽  
Zita Pánczél ◽  
Sándor Valent
Keyword(s):  
De Novo ◽  
Clinical Symptoms ◽  
Severe Disease ◽  
Multiple Organ ◽  
Common Denominator ◽  
Stage Model ◽  
Two Stage ◽  
Organ Systems ◽  
Stage 1 ◽  
Oxide Synthase

Preeclampsia is a common and severe disease in pregnancy, a major cause of maternal and fetal morbidity and mortality. The main features of the disease are de novo hypertension after the 20th gestational week and proteinuria, and it is frequently accompanied by edema and other subjective symptoms. The origin of the disease is the placenta, but its sequelae affect multiple organ systems. According to the two-stage model of preeclampsia, the abnormal and hypoperfused placenta (stage 1) releases factors to the bloodstream, which are responsible for the maternal symptoms (stage 2). Oxidative stress, impaired function of nitric-oxide synthase, cellular and humoral immunological factors play an important role in the pathophysiology of the placenta. Endothelial dysfunction is the common denominator of the clinical symptoms. The theory explains the origins of hypertension, proteinuria, edema and other symptoms as well. Orv. Hetil., 2012, 153, 1167–1176.

scholarly journals DRP1-mediated mitochondrial fission is essential to maintain cristae morphology and bioenergetics

2022 ◽  
Author(s):  
Gabriella L. Robertson ◽  
Stellan Riffle ◽  
Mira Patel ◽  
Andrea Marshall ◽  
Heather Beasley ◽  
...  
Keyword(s):  
Cell Fate ◽  
De Novo ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Coupling Efficiency ◽  
Acid Oxidation ◽  
Mitochondrial Morphology ◽  
Missense Mutations ◽  
Neurodevelopmental Disease ◽  
Signaling Organelles

Mitochondria and peroxisomes are both dynamic signaling organelles that constantly undergo fission. While mitochondrial fission is known to coordinate cellular metabolism, proliferation, and apoptosis, the physiological relevance of peroxisome dynamics and the implications for cell fate are not fully understood. DRP1 (dynamin-related protein 1) is an essential GTPase that executes both mitochondrial and peroxisomal fission. Patients with de novo heterozygous missense mutations in the gene that encodes DRP1, DNM1L, present with encephalopathy due to defective mitochondrial and peroxisomal fission (EMPF1). EMPF1 is a devastating neurodevelopmental disease with no effective treatment. To interrogate the mechanisms by which DRP1 mutations cause cellular dysfunction, we utilized human-derived fibroblasts from patients with mutations in DRP1 who present with EMPF1. As expected, patient cells display elongated mitochondrial morphology and lack of fission. Patient cells display a lower coupling efficiency of the electron transport chain, increased proton leak, and upregulation of glycolysis. In addition to these metabolic abnormalities, mitochondrial hyperfusion results in aberrant cristae structure and hyperpolarized mitochondrial membrane potential, both of which are tightly linked to the changes in metabolism. Peroxisome structure is also severely elongated in patient cells and results in a potential functional compensation of fatty acid oxidation. Understanding the mechanism by which DRP1 mutations cause these metabolic changes will give insight into the role of mitochondrial dynamics in cristae maintenance and the metabolic capacity of the cell, as well as the disease mechanism underlying EMPF1.

Microprobe analysis of inclusion bodies related to two benzofuran derivatives

1987 ◽  
Vol 45 ◽  
pp. 672-673
Author(s):  
T. L. Benning ◽  
P. Ingram ◽  
J. D. Shelburne
Keyword(s):  
Inclusion Bodies ◽  
Uranyl Acetate ◽  
Multiple Organ ◽  
High Dose ◽  
En Bloc ◽  
Tissue Samples ◽  
Transmission Electron ◽  
Organ Systems ◽  
Dense Inclusion ◽  
Melanin Complex

Two benzofuran derivatives, chlorpromazine and amiodarone, are known to produce inclusion bodies in human tissues. Prolonged high dose chlorpromazine therapy causes hyperpigmentation of the skin with electron-dense inclusion bodies present in dermal histiocytes and endothelial cells ultrastructurally. The nature of the deposits is not known although a drug-melanin complex has been hypothesized. Amiodarone may also cause cutaneous hyperpigmentation and lamellar lysosomal inclusion bodies have been demonstrated within the cells of multiple organ systems. These lamellar bodies are believed to be the product of an amiodarone-induced phospholipid storage disorder. We performed transmission electron microscopy (TEM) and energy dispersive x-ray microanalysis (EDXA) on tissue samples from patients treated with these drugs, attempting to detect the sulfur atom of chlorpromazine and the iodine atom of amiodarone within their respective inclusion bodies.A skin biopsy from a patient with hyperpigmentation due to prolonged chlorpromazine therapy was fixed in 4% glutaraldehyde and processed without osmium tetroxide or en bloc uranyl acetate for Epon embedding.

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